


Nothing He Wouldn't Do

by mokuyoubi



Category: Supernatural
Genre: Brothers, Demon Dean Winchester, Dubious Consent, M/M, Top Dean, Wincest - Freeform, depending on how you look at it, in conclusion, spoilers through 10x03
Language: English
Status: Completed
Published: 2014-12-03
Updated: 2014-12-03
Packaged: 2018-02-28 01:22:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,534
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2713745
Author URL: https://archiveofourown.org/users/mokuyoubi/pseuds/mokuyoubi
Summary: <blockquote class="userstuff">
              <p><i>You notice I tried to get as far away from you as possible?</i> My take on why Dean's behaviour shifted radically from harmless asshole to Jack Torrance-esque killer the second Sam showed up, and what might have happened if Castiel hadn't appeared in the bunker when he did.</p>
            </blockquote>





	Nothing He Wouldn't Do

Sam ducked the hammer and turned, bringing up the demon blade. There was a flash of surprise in Dean's eyes, quickly covered by that sinister confidence. It was just a shade different from his usual smugness; no one but Sam might even notice.

Sam couldn't quite control his breathing or the rapid beating of his heart, and it wasn't just adrenaline. It was ridiculous, because he'd faced worse than Dean a thousand times over in his life, but he'd never been as terrified of anything as he was now. Death was a prospect Sam had made peace with long ago, but the idea of dying at Dean's hands was different in a way he didn't entirely understand.

“Well, look at you.” Dean parted his lips, something like approval in his expression. “Do it. It's all you.” He leaned into the blade and bared his teeth. He'd called it a game and was treating it like one, because he had to know, no matter what Sam said, he wouldn't... _couldn't_. That's why he needed Cass, who was still no where to be seen.

There was a momentary flicker of disappointment on Dean's face when Sam lowered the blade. Then Dean's lips twisted up in a sick approximation of a smile and his eyes went black. He surged forward, and even if Dean weren't juiced up with demon strength, Sam would have been at a disadvantage. Dean caught his good wrist and twisted hard, slamming Sam face first into the wall and pinning his arm up behind him. 

Sam gritted his teeth against the grunt of pain and the blade clattered to the floor. Dean was pressed against his back, face close, breath hot on Sam's neck. “Should have run away when you had the chance, Sammy,” Dean said. “Should have let me stay gone.”

Sam shook his head, and they both knew all the words he wasn't saying. That he couldn't have done either, just as Dean wouldn't have, had the situation been reversed. That no matter what Sam had said before, about not doing the same Dean had done with Gadreel, had things been reversed...he'd been lying. 

Because they couldn't just _let_ each other go. Sam had tried that once, with Amelia, and it had tinged every moment that had followed with regret, something that had only recently started to fade before... Before Sam had learned about Gadreel and Dean had gone off and gotten himself marked by the original Knight of Hell.

The hammer was stuck in the wall by Sam's head and he was waiting for Dean to grab it again, bracing himself for the blow to follow. But Dean's free hand came up to grab Sam's throat and jerked him away from the wall. Sam stumbled the first few steps as Dean propelled him down the hall.

“You had to come after me, didn't you? The _one time_ I don't want you to come after me, and you couldn't go find yourself another wounded bitch.”

Sam swallowed back the urge to respond. It was foul even for Dean; the demon was trying to get a rise out of him but Sam wouldn't give it the satisfaction. 

Dean stopped suddenly, Sam's momentum choking him on Dean's hand, as Dean jerked him back sharply, pressed together head to toe. “I was trying to do you a favour.”

“Right,” Sam muttered. He couldn't fight a sneer. “Doing me the favour of not having to cure your ass.”

“That's never going to happen,” Dean growled. Then his tone changed suddenly and completely, light-hearted and conversational. “You know, being a demon and having no soul, different side-effects, but the symptoms are pretty much the same when you get right down to it. What you don't get is that I'm still me, Sammy, just the way you were still you, when Crowley brought you back from the pit. When you let me think you were dead for a _year_.”

He nudged Sam forward again, making his shoulder and wrist twinge. “My brother wouldn't have left me to die at the hands of some misguided psychopath,” Sam said, keeping his tone even.

“You mean the way you let me be turned into a freakin' vampire?” Dean said, chuckling in real amusement. “Oh, there's a lot of things your brother wouldn't do because of how he feels about you.”

They'd come to Dean's door and now Dean shoved them through it, sending Sam sprawling across the room as Dean shut and locked the door behind him. Sam caught himself before he fell and turned to lean against the wall, watching Dean warily. He was standing just inside the door and he didn't look particularly threatening, but Sam could read the menace in the quirk of his lips, his hooded eyes that weren't demon black any longer, but brighter than usual.

“You know what I did with Crowley these past couple months?”

Mostly, Sam didn't want to know, could already feel the bile rising in his throat in anticipation of what he'd hear. But he had to know, all the same. Like a scab he couldn't stop picking at, though he knew it would never heal right.

“Drinking, screwing, and killing demons,” Dean said, arms spread, wide, disingenuous smile on his face. “Family business, though I have to tell you, it's a lot more fun without your constant bitching and nagging. _Oh no, Dean, we can't kill the_ nice _monsters. Gee Dean, did ya go a little overboard killing that bad guy? How_ dare _you save my sanctimonious ass when I never asked you to,_ blah, blah, blah.” 

Dean rolled his eyes and strolled towards Sam. His pace was slow, his posture casual, but Sam wasn't fooled. “No one making me feel guilty. About anything.”

“Dean,” Sam started, and stopped himself, because there was no point in trying to appeal to deal, to apologise, other than to give him more ammunition.

“Yeah,” Dean said in agreement, like he knew exactly what Sam was thinking. “You'll wanna be saving those pleas. You wanna know the only real difference between me and _your_ Dean? I _will_ do those things to you 'cause of how I feel about you.”

Sam tipped his chin back, jaw set, and shook his hair from his eyes. “And what's that supposed to mean?”

Dean took the last step between them, put a hand to Sam's chest and shoved. And Sam—he brought up a hand to grab Dean's wrist. Or he meant to, but couldn't move. It was different from being pinned by other demons. Not a force physically holding him back, but almost as though he no longer had control of his limbs. He could tell his body how to respond, but it wasn't listening.

Sam fell back against the wall on his shoulders, body tilted at an angle, hips thrust forward. He couldn't right himself, couldn't push against or away from Dean's touch. He could only watch with mounting disbelief and panic as Dean moved again.

“Don't worry,” Dean said. His hand slid down Sam's chest, stopping at his waistband. He looked down at where his thumb dragged along the buckle of Sam's belt before meeting Sam's gaze. “I'll show you _exactly_ what I mean.”

Dean's fingers slipped beneath denim, knuckles rough on Sam's skin. With a quick, jerking movement Dean undid the belt and ripped it free of its loops, tossing it behind him. Sam sucked in a breath and then let it out, panting Dean's name. Apparently his mouth was still under his control. “What--”

Quick as a snake, Dean was in his space, teeth bared, inches from the skin of Sam's neck, and Sam distinctly remembered the day before in the bar, Dean threatening to rip his throat out. One hand easily flicked open the button fly of Sam's jeans and pulled down the zipper. And suddenly Sam's mouth was dry and he could barely hear over the thudding of his own heart because never in his wildest imagination could he have anticipated this. 

Dean pressed his face to Sam's throat and Sam could feel the sharp cut of his smile, followed by the sharper edge of his teeth, scraping over skin, just hard enough to bruise. Goosebumps sprung up along the backs of Sam's arms, the hair at the nape of his neck rising. Dean made an amused sound when the heel of his palm, nudging against Sam's boxers, met a growing hardness.

“Well lookie here,” Dean drawled, head bowed to glance between them as he shoved Sam's jeans and boxers down over his hips. Sam closed his eyes, but could still imagine the expression on Dean's face. He wished he could blame the lack of control over his body, but the truth was, his response to Dean's closeness, Dean's intimate touch—it wasn't unexpected, or even anything new. No that, shamefully, was all him.

His body would have jumped, if it could, as Dean drew a finger along the length of Sam's dick. Dean whistled low in appreciation. “Sammy, Sammy, Sammy,” he cooed. “If I'd known you'd be so _eager_ \--” there was a sudden shift and the sound of Dean's knees hitting the floor. 

Sam groaned in mingled disgust and longing. “Dean, no--”

Dean's hands closed around Sam's thighs tightly, nails digging in painfully. “Dean, yes,” he growled, and that was all the warning Sam had before Dean's mouth closed around his dick, hot and wet.

Sam's body clenched tight with all the warring reactions, the desperate attempt to jerk away and thrust his hips deeper, and being able to do neither. Dean hummed and Sam's eyes rolled up into his head. 

Dean had no right to be so good at sucking dick, pulling out all the stops to have Sam shaking in desperation, balls pulling tight within minutes. It had been a long time since anyone had touched him like this, but that wasn't the only reason he was so close, so quickly. It had everything to do with _who_ was on his knees, and the thought was sobering, made Sam grunt out, “Please.”

There was a slick, lewd _pop_ as Dean sat back, letting Sam's dick fall from his mouth. Sam let out a whimpering noise, whether from relief or loss, it was impossible to say. His brain screamed at his hips to move, to pump forward and come all over Dean's face.

And Dean, he was still and silent. Sam opened his eyes and forced himself to look. Dean's mouth was obscene, red and swollen, a thread of saliva still hanging from the tip of Sam's cock stuck to his bottom lip. Sam took a centring breath, closing his eyes briefly before meeting Dean's.

“Say it again, Sammy,” Dean said, and for a second, he was Sam's Dean, lost, pleading, broken. It passed in the blink of an eye, but it was enough to tell Sam it was working. The blood was doing its job. Then Dean smirked and his eyes went black. “Just make sure you know what you're asking for.”

Sam had _no idea_ what he was asking for, but the word fell from his lips all the same, eyes sliding closed in the same instant. “Please.”

Dean was radiating smug amusement and Sam felt a strange relief sink through his muscles. It took him a second to realise what it was, when Dean sucked him down and Sam's hand came up to grab a fistful of hair and he thrust down Dean's throat. He didn't have time to really think about regaining control of his body before he lost it again when Dean swallowed around the head of his dick. Sam saw white against the black of his lids as spasms tore through him, body going taut. He came harder than he'd ever fucking come in his life, like Dean was ripping it out of him with his goddamned mouth.

“Tell me,” Dean said, voice even hoarser than usual, but otherwise completely nonchalant, wiping his mouth with his sleeve as Sam slumped against the wall, still catching his breath, vision splotchy. “What's worse? Me taking off? Coming after you with a hammer? 

“Or,” Dean drawled, rising effortlessly to his feet, unfastening his jeans. Sam couldn't help glancing at the bulge there, couldn't let his eyes linger even now, “me making you beg me to fuck you?”

Sam didn't answer, mostly because he wasn't sure what his answer would be. He swallowed hard, tongue shoved against his teeth, a barrier to a million things he might say. Dean grabbed him by his good elbow and half dragged him across the room to the bed, Sam tripping along the way, still light-headed, and off balance with his jeans still around his thighs. He fell face first on the bed, grunting as his bad arm took the brunt of his weight.

“Aw, baby,” Dean purred sarcastically. “Let's take your mind right off it.” Sam watched him fish around in the bedside drawer and tried to push up on his knees, get some sort of leverage. Dean was back at his side in an instant, hand on his back effortlessly pushing him down.

“Don't get me wrong,” Dean said. “I appreciate the effort keeping up the act. But, you're not fooling anyone. I think you've made it pretty damn clear--” cold, slick fingers brushed along the curve of Sam's ass, seeking “--just how much you want it.”

“Ah,” Sam canted his hips, entirely without meaning to. “Dean, I know you're in there.”

Dean leaned in close, pressed against Sam's back and his lips brushed Sam's ear. “I've been telling you all along, I'm _right here_. I'm just doing what I was too pussy to do before—taking what I want.” His fingers prodded lower, until he found what he was looking for, pressing inward mercilessly. Sam's body spread open for the intrusion, to his intense disbelief.

“You think appealing to your brother's going to help you?” Dean asked, two fingers stretching and pushing deeper inside Sam. His teeth closed around Sam's ear, biting hard then soothing with his tongue. 

“Like he didn't think of doing this exact thing to you for _years_ \--” Now three fingers, stinging, too dry. Sam clinched his eyes shut tight and tried to relax into it, to ease the burn. “--as long as he can remember, listening to you breathe in the next bed while Dad was out on a hunt, feeling sick with guilt, disgusted by how he wanted to touch his baby brother, the one he was supposed to be protecting, worse than any monster out there. Getting hard whenever you wrestled and running off to the shower, fucking every willing chick to try to convince himself he was normal.”

“Even now, even with no inhibitions, trying to _spare_ you, but you couldn't leave well-enough alone.” Dean roughly pulled his fingers free and Sam only had a moment to adjust to the relief before Dean was shifting, the blunt head of his cock nudging Sam's hole. Dean's slick fingers grabbed Sam's hips, tilting his ass upward.

The thing was, Sam could have fought. Even one-armed he wasn't helpless, and they both knew it. They both knew he wanted this, and that burned worse than the slow glide as Dean thrust his cock home, past the resistance. Sam's thighs strained against the confines of his jeans, trying to spread wider and make it go more smoothly. He was hot and cramped and it was so tight. 

Little jerks of Dean's hips drove him further. They rocked together, no use in Sam trying to deny he wanted it any longer, mouth hung open on an unspoken plea, needing Dean closer. Dean pulled back only to sink in again, making it a little deeper each time, fighting for each inch. He grunted, sweaty forehead pressed into the back of Sam's neck. Sam arched his spine into it, doing what he could to take him entirely. Dean's hand drew down his back, _petting_ him, pleased by him, and Sam felt as though his every atom was straining into the touch, then the whole damn tone of the thing changed. 

Dean's hands were suddenly clinging to Sam, sliding over sweat-slick skin up his hips, under his shirt, arms wrapping tight and clinging. His shaking, uncertain fingers dug into Sam's chest and he thrust deep, hitting Sam in just the right spot. Sam felt it in his fucking teeth, it was so fucking good. All Dean's skill and finesse were gone.

“Dean?” Sam said, good hand worming between his body and the mattress, winding under layers of clothing to find Dean's hand and lace their fingers together.

Dean didn't answer in words, just held tighter, grinding into Sam with a desperation that made Sam's chest ache. He was hard again, cock throbbing insistently, and he was starting to think he might just come from this, Dean humping him like they were two teenagers going at it for the first time in the back of their dad's car. 

Like Sam hadn't thought of that before, hadn't had all those same shameful, lewd thoughts Dean had, seeing Dean with his girlfriends, imagining taking their place. Hell, at this point Dean could just rub up against him and Sam would spend himself like a two-pump chump, because this was his Dean, fumbling for him, panting against his neck, licking and sucking marks into his skin.

“Sam,” Dean cried, and he was coming, hot and slippery, suddenly making everything a lot easier, because he kept thrusting. Kept working his hips in tight little circles as he gasped through it, calling Sam's name again. Softer, wondering.

Sam's jaw set tight, muscles drawing tight in anticipation, straining towards orgasm. He turned his head to the side, to see Dean watching him, eyes flashing with a dozen conflicting emotions Sam knew mirrored his own. Sam shuddered, thighs stinging at the effort to push wider and somehow the discomfort made the pleasure that much stronger and he started to shake apart.

Dean pulled out, a shock of sensation, leaving Sam feeling stretched too wide and empty, Dean's come leaking between his ass cheeks and down his thighs. His finger's traced Sam's hole, making him shake and jerk as he came. Dean leaned over him, dick starting to soften in the small of Sam's back. His weight was reassuring, pressing Sam into the mattress with every harsh breath.

Sam's eyes drifted down to Dean's mouth and back again, and then Dean caught him in a hungry kiss. And this, more than anything else they'd done, was admitting too much. This messy tangle of tongues and teeth telling more than words.

Dean bit down hard on Sam's bottom lip, hard enough to draw blood. He mumbled against Sam's mouth, still sucking, “Do it now, Sam.”

Sam couldn't think past the daze of confused regret and satisfaction and the desire to keep licking into Dean's mouth, to roll them over, chest to chest, revelling in the way Dean's hands tangled in his hair, gentle now. Dean tore his mouth away and bit Sam's throat, his shoulder, stinging even through layers of clothing. “You have to do it now.”

“Do--” Sam echoed, pushing up on the elbow of his good arm as Dean withdrew from him. 

Dean staggered back, face pale, tugging on his pants and falling backward into his arm chair. A bunch of pictures fell from the arm and scattered across the floor. Sam could see his parent's faces and Bobby's smiling up at them. Dean and himself grinning as if they didn't have a care in the world. It was such an alien concept he almost couldn't remember the man he'd been in those pictures. 

“Finish it,” Dean managed, through clenched teeth, and pinned Sam with his glare. “Now.”

The confusion cleared and Sam struggled to his feet, jerking his jeans up one handed, high enough to get them to stay on his hips. He grabbed Dean by the arm and hauled him out of the room, down the hall.

Dean didn't fight him when Sam pushed him into the chair. He didn't bother with the restraints, turning to grab a syringe. When he turned back Dean's hands were clenched tight against the arms of the seat, fingers going white, and he looked up at Sam, gaze unreadable.

“Dean,” Sam said, warning, pleading, he didn't even know any more. This could kill him, and the demon had known Sam better than he knew himself, because he knew Sam couldn't take that last step.

Would it be so horrible to let things stay this way? Sam knew soul deep that the demon wouldn't try to kill him again. He was certain now that had never been the demon's intention in the first place. Only to scare him enough that when he ran again, Sam wouldn't follow. To save Sam from what they'd both ignored for two long. Would continue to ignore, for the rest of their lives.

“Sammy, please,” Dean said, voice broken. Sam's body moved entirely on instinct, like fucking Pavlov's dog, Dean's voice the ringing of a bell. He shoved the needle into Dean's arm and didn't think, just pushed the plunger.

(maybe the end?)

**Author's Note:**

> I know it's an abrupt ending, but this was supposed to basically fill in from where Cas would have showed up to when they get Dean back in the seat and he wakes up all demon-free. Honestly, as I watched all of season 10 so far in two nights, I felt like I could keep this narrative going, filling in with the story so far, but I just wanted a quick, smutty one-shot, so I made myself stop.
> 
> Thanks to my big sister, [Pinkglittermasturbation](http://archiveofourown.org/users/PinkGlitterMasturbation/pseuds/PinkGlitterMasturbation), for her beta...and no, that wasn't awkward at all, asking her to beta Wincest...
> 
> Next up, the Destiel version :D


End file.
